esm_loader.mjs

esm_loader.mjs

import { createRequire } from 'node:module'
import { delimiter } from 'node:path'
import { pathToFileURL } from 'node:url'

const extraNodePaths = (process.env.NODE_PATH || '')
  .split(delimiter)
  .filter(Boolean)

export async function resolve(specifier, context, defaultResolve) {
  try {
    return await defaultResolve(specifier, context, defaultResolve)
  } catch (originalError) {
    if (specifier.startsWith('.') || specifier.startsWith('/') || specifier.match(/^node:/)) {
      // Don't handle relative, absolute, or node: specifiers
      throw originalError
    }

    for (const basePath of extraNodePaths) {
      const require = createRequire(pathToFileURL(basePath).href)
      try {
        const resolved = require.resolve(specifier)
        return { url: pathToFileURL(resolved).href }
      } catch {
        // Skip and try next
      }
    }

    // Re-throw original error if not found
    throw originalError
  }
}